Field of the Invention
The present invention relates to a fixing apparatus having a heating unit for heating a recording material by using a cylindrical rotating member having flexibility, and relates to an image forming apparatus having this fixing apparatus.
Description of the Related Art
Image forming apparatuses based on an electrophotographic system include an apparatus for fixing a toner image onto a recording material by heating and pressurizing the toner image formed on the recording material.
FIG. 11 illustrates an example. An example of this fixing apparatus includes, for example, what is described in the publication of Japanese Patent Laid-Open No. 2005-92080. This includes a cylindrical fixing belt 201 having flexibility (cylindrical rotating member), a halogen heater 202 serving as a heating unit, a fixing member 203 (sliding member), and a pressure roller 204 serving as a pressure member. The fixing belt 201 is driven and rotated according to rotation of the pressure roller 204. The fixing member 203 is fixed inside of the fixing belt 201, and forms a nip between the fixing member 203 and the pressure roller 204.
The recording material 206 is conveyed from the right side of FIG. 11, and the toner is fixed in the nip. The halogen heater 202 heats the fixing belt 201 with radiant heat, but in order to efficiently provide heat to the fixing belt 201 without giving heat to the fixing member 203, a reflection member 205 is installed at the position between the halogen heater 202 and the fixing member 203. Such fixing method is characterized in having superior power saving performance since the heat capacity is low.
However, in this configuration, there is a movement of heat from the fixing belt 201 to the fixing member 203, and because of this movement of heat, it is difficult to increase the temperature of the fixing belt 201, and there is a problem in that the fixing apparatus cannot be started in a short time.